- Cardiac conduction abnormalities denoted by any of the following: evidence of second-degree (type II) or third-degree atrioventricular block, evidence of ventricular pre-excitation, electrocardiographic evidence of complete left bundle branch block (LBBB), intraventricular conduction delay with QRS duration >120 msec, evidence of atrial fibrillation or history of atrial fibrillation within the past 6 months or presence of cardiac pacemaker